Intern Bike Review

Rocky Mountain Thunderbolt 770

Words Matthew Lee
Photos Kaz Yamamura, Cam McRae, Pete Roggeman
Date Oct 27, 2014

A year ago if you had told me I would enjoy climbing on a bike, and not just suffering through to the descent, I would have laughed in your face. Yet here we are after nearly 3 months on the Rocky Mountain Thunderbolt 770, and humble pie has never tasted better.

Pitched by Rocky as a cross country/trail bike blend with 120mm of travel (a fun XC bike if you will), 2014 was the first production year for the Thunderbolt. I rode a mid-spec powder blue bike in April as part of my mission to climb 10 thousand feet in a week, but without riding beyond my local trails I couldn’t assemble a complete picture of its capabilities. I was positively giddy when I found out I’d be riding the top-end 770 model as my Intern Bike; here was my chance to see just how far I could push this trail whippet.


The stealth speed machine. This beast and I would have a lot of fun in the coming months… Photo: Kaz Yamamura

The whole idea behind the Intern Bike concept was simple: fellow intern Kaz Yamamura and I were to find a wallet-friendly bike that matched our riding preferences and record the adventures that followed. After a quick look over the spec, it was time to head out on an adventure. My first time out on the Thunderbolt certainly fit the bill with a wild ride down Microclimate in Whistler. Sitting at the bottom of the trail covered in dust, I knew the Thunderbolt and I were going to have a lot of fun together.


Pictured: having so much fun, it should probably be illegal… Photo: Kaz Yamamura

The Up:

Pedalling up on the  27-pound Thunderbolt felt a bit like cheating compared to other bikes I’ve ridden. A lightweight wheel set composed of 650b sized Stan’s ZTR Crest rims laced to Shimano XT hubs kept the rotational mass down, and an upright seated position ensured hours of comfort in the saddle. Standing 179cm tall (5’10” in Imperial), I found the top tube length a tad on the small side, but not cramped. The rest of the fit was spot-on, and that’s really what helped me get the power down.

Step down hard on the pedals, and you’ll rocket forward at a pace usually reserved for something much spindlier. Put a technical section of climbing in front of the bike, and it’ll help you solve it like the president of MENSA. The combination of short chainstays and a 68.5 degree head angle mean the bike is agile enough to thread through tricky root sections and scoot over obstacles on the trail. Some riders may point to the 2 x 10 XT drivetrain as a relic but I liked having a granny gear to sit and spin in, especially during long, steep fire road climbs.


Wet, rooty, ugly? Doesn’t matter, the Thunderbolt is as steady on the climbs as a mountain goat. Photo: Kaz Yamamura

When I left the shock and fork in the full-open position, pedalling would cause a small amount of bob. Thankfully, Rocky has equipped the Thunderbolt with a remote lever that switches the settings on both the CTD shock and fork simultaneously. I used the Climb, Trail and Descend modes as intended, and got a kick out of locking the suspension while putting the hammer down in punchy little climbs.


The CTD remote takes up a scant amount of space on the bar, and has proven itself to be quite useful. Photo: Kaz Yamamura.

The Thunderbolt has made my time climbing far more enjoyable than before, and I get a small sense of satisfaction by simply cruising past people on the way up the hill with a smile and a wave.

The Down

Tackling the descents on the Thunderbolt is an exercise in grin widening, but push things too far and it will quickly tell you to back off. The trick is to find out where that line is, and hold onto it for as long as possible.

The Fox RP23 rear shock has an extremely progressive curve rate, staying quite supple off the initial stroke, but ramping up so much by the end of its travel that I never noticed bottoming out the shock, even when the sag ring made it all the way to the end of the stanchion.  Up front, the FIT damper in the Fox 32 fork made for a supple ride, but it’s worth mentioning that the fork sits closer to the XC side of the spectrum, and as a result I did experience some deflection when riding in aggressive terrain.


It’s easy enough to find XC-friendly trails on the Shore, but it’s even easier to get yourself into trouble quickly. Photo: Kaz Yamamura

That same head angle that makes the Thunderbolt agile when climbing makes specific demands during the descents. Unlike slacker bikes, the Thunderbolt requires a very active and front-weighted riding style. Backseat driving is punished with sloppy cornering and awkward tire placement. Stay on top of the bike, and you’ll be rewarded with snappy corner exits while dancing down the trail.


I could honestly ride singletrack like White Tail near Naramata in B.C.’s wine country for days on end and never get bored. High speed smooth terrain is where the Thunderbolt truly struts its stuff. Ending up at Hillside Winery for a tasting wasn’t too shabby either. Photo: Cam McRae

The limitations of the Thunderbolt are revealed when the terrain gets technical and chunky for extended periods of time. I did two major trips with the bike (a heli-drop above Tenquille Lake, and shuttling in the Okanagan) that exposed me to riding that was simply beyond both the intended use of the bike and my own skill level. While the bike survived the encounters with extended steep and deep chunder I definitely experienced some fade in the XT brakes due to smaller rotors, and was decidedly slower than my companions on bigger bikes.


While the Thunderbolt was adequate once the terrain got chunky on Rainbow near Penticton, riding a bigger bike would have likely resulted in more fun. It would also require wearing longer shorts though… Photo: Cam McRae

In contrast, the Thunderbolt is in its element on smoother, flowy singletrack. Simply let off the brakes, pump and pop your way down the trail and hunt down anyone you didn’t pass on the way up. Given its climbing prowess and the ability to outperform a traditional XC bike on the descent, the Thunderbolt would certainly be a contender for people looking to do a multi-day stage race like the BCBR, the Singletrack Six, or longer technical XC races like the Nimby Fifty.


More drifty goodness – this time riding Cawston Creek Trail above Keremeos, B.C. This is also the default face position for Thunderbolt riders: a big grin, with just a hint of “oh my goodness!” Photo: Pete Roggeman

Maintenance and Mods

Over the three months I’ve spent with the bike, there have been zero frame issues. The only thing I’ve had to replace were the brake pads, and I re-greased the bushings at the two month mark. Otherwise, there has been zero creaking or groaning between my legs.

I’ve made a few changes to the Thunderbolt’s component spec during the test period. The biggest change saw the stock bar and stem swapped out for a 50mm Gamut Cillos stem paired with some 780mm Chromag Fubar OSX bars. I personally prefer the setup I have now but understand why the bike came equipped as it did, and in different terrain I would likely have left everything as it was.

The other change is the tires, where I swapped the provided 2.2″ Continental X-Kings for a 2.4″ Maxxis Highroller II 3C EXO in the front and a 2.4″ Ardent EXO in the rear. The logic behind this swap was simple: the XC tires would do well in a dry hardpack environment, but were questionable at best in the wet and technical North Shore environment. Given that winter is now upon us, the pinner tires had to go.


When the going gets slick, the tires get thick. Out here, grip is everything. Photo: Kaz Yamamura

My only other spec-related complaint is the lack of a dropper post. I understand that a dropper may be considered superfluous on an XC machine, but having gotten used to one on other bikes it was rather jarring to go back to a fixed post and QR seat collar. Thankfully, Rocky have pre-empted my beef, and the 2015 MSL Thunderbolts all sport either a Rock Shox Reverb or Xfusion HiLo depending on spec.

Keeping on the future theme, the Thunderbolt sees a number of changes for 2015, the biggest of which is a new carbon frame with a Ride-9 chip. The Ride-9 chip allows the rider to alter the geometry of their bike via a series of rotating pieces in the shock mount. There will also be a BC Edition, which features slightly slacker geometry, 130mm of travel, and a beefier component spec.

Those who don’t have a ton of cash to splash on a bike needn’t worry about being cut out of the market either; Rocky will be carrying the current aluminum frame over into next year with a series of even more wallet-friendly setups. The current Thunderbolt 770 model retails for $4099 CAD, with 2015 models ranging from an eye-watering $11,499 CAD for the XTR Di2 kitted 799 model to a much more wallet friendly $2099 for the entry level 710.

Overall, I’ve quite enjoyed my time spent aboard the Thunderbolt. It’s managed to change my perspective on climbing as a sufferfest to something resembling enjoyment. The ride down is equally fun, provided you don’t stray too far into the techgnar at high speeds. My few nitpicky issues with the bike have all been resolved with the 2015 models, and there are still affordable models in the Thunderbolt lineup.

Riders looking for an endurance race rig and those who are looking to have fun on the climbs should definitely give the Thunderbolt a close look. As for me, I’ll be sure to give you a smile and a wave on the way up.

Does the thought of a shorter-travel climb machine give you a tingling sensation?

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6 years, 7 months ago

Just curious, what size bike did you test? I'm 5'10.5″ so I was wondering how the bike fit you.


7 years, 6 months ago

Just want to mention that it's actually a Float CTD Evo out back, not an RP23. Otherwise great review from the intern! 🙂


7 years, 6 months ago

Maybe it was the shocks in pic 6&7 that held you back on the downhills? Just saying…


7 years, 6 months ago


Jonathan Harris
7 years, 6 months ago

Shocks or the really long socks? 😉


Matt Lee
7 years, 6 months ago

I do tend to favour the longer sock. It gives me a sense of security when I ride.


7 years, 6 months ago

wonder if they have a similar effect to a thundershirt?


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